Heaven's Gate

Color-changing effects are one of Magic's oldest pieces of utility design, and this is the white, instant-speed, multi-target version of the toolkit. It exists because of the rules vocabulary of its era, when a creature's color was itself a variable that other cards keyed off: protection-from-a-color wording, white-matters triggers, and effects that cared whether your team was the right color all turned a one-mana mass recolor into a connective piece. On its own, Heaven's Gate does nothing; the card cannot grant protection, cannot target a spell on the stack, and does not save a creature from anything that ignores color (a white creature is still a legal target for color-blind removal). What it does is let you decide what color your board counts as for a turn, so a static protection effect or a color-conditional trigger can be switched on at instant speed. There is a quiet flavor joke buried in it, too: white being the color that literally turns things white. The card dates not because of its cost but because the rules it was built to manipulate grew more uniform; protection wording standardized, removal stopped keying off color the way some early black and red spells did, and the niche a cheap mass color-change once filled largely evaporated. It survives as evidence of a period when a creature's color was a defensive lever you could rewrite mid-combat, with white holding the broadest and cheapest access to the trick.